Related Experiment Video
Updated: Jun 4, 2026
Monitoring Dynamic Growth of Retinal Vessels in Oxygen-Induced Retinopathy Mouse Model
Published on: April 2, 2021
Screening for retinopathy of prematurity in infants born before 27 weeks' gestation in Sweden
Dordi Austeng1, Karin B M Källen, Ann Hellström
1Department of Neuroscience, Uppsala University, Uppsala, Sweden.
Insights
Screening for retinopathy of prematurity (ROP) in extremely preterm infants can be safely initiated later. The study found that ROP treatment criteria were not met until later postmenstrual ages, suggesting adjusted screening schedules are possible.
Area of Science:
- Ophthalmology
- Neonatology
- Public Health
Background:
- Retinopathy of prematurity (ROP) is a significant cause of vision impairment in preterm infants.
- Early detection and treatment of ROP are crucial to prevent severe visual outcomes.
- Current screening guidelines recommend starting ROP examinations early in extremely preterm infants.
Purpose of the Study:
- To analyze the screening practices for retinopathy of prematurity (ROP) in a national cohort of infants born before 27 weeks' gestation.
- To determine the optimal timing for initiating ROP screening in extremely preterm infants.
- To evaluate if current screening protocols align with the actual onset of treatable ROP.
Main Methods:
- A prospective national study of neonatal morbidity in extremely preterm infants in Sweden (2004-2007).
- ROP screening initiated in the fifth postnatal week and continued weekly.
- Data collected on examination timing, ROP development, and treatment initiation.
Main Results:
- 84.8% of 506 infants had their first eye examination by the sixth postnatal week.
- The mean number of ROP examinations was 12 per infant, with examinations occurring every 7-8 days on average.
- Treatment for ROP was initiated for most infants by postmenstrual age (PMA) of 39 weeks.
Conclusions:
- In infants born before 27 weeks' gestation, ROP screening can be safely postponed until PMA of 31 weeks.
- The onset of ROP stage 3 and criteria for treatment were not met before PMA of 32 weeks in this cohort.
- Gestational age at birth and PMA at examination are key factors for optimizing ROP screening schedules.
Objective:
To analyze screening for retinopathy of prematurity (ROP) during a 3-year period in a national cohort of infants born before 27 weeks' gestation.
Methods:
A national prospective study of neonatal morbidity in extremely preterm infants was performed in Sweden between April 1, 2004, and March 31, 2007. Screening for ROP was to start in the fifth postnatal week and to continue weekly until complete vascularization of the retina or until regression of ROP.
Results:
The first eye examination was performed no later than the sixth postnatal week in 84.8% of 506 infants, and the last examination was performed at postmenstrual age (PMA) of 38 weeks or later in 96.2% of infants. The mean and median numbers of days between examinations in the total cohort were 8.6 and 7.9 days, respectively (range, 1-27.8 days), and the mean and median numbers of examinations were 12 and 10, respectively. Most infants were treated during a limited period (eg, at PMA of 39 weeks, 75.0% of infants had been treated).
Conclusions:
The objective of screening for ROP is timely detection of ROP before reaching treatment of criteria, ie, type 1 ROP, according to the Early Treatment for ROP recommendations. In our population of infants born before 27 weeks' gestation, the first examination could safely be postponed until PMA of 31 weeks because the onset of ROP stage 3 did not occur before then and criteria for treatment were not reached before PMA of 32 weeks. Gestational age at birth and PMA at the time of examination should be considered when deciding when and where the next examination should be performed.
